Compute linear model contrast statistics (public API) — compute_lm

A polished wrapper around the internal fast contrast engine. Accepts name-based contrast specifications and returns a consistent tibble by default.

Usage

compute_lm_contrasts(
  B,
  XtXinv,
  df,
  sigma = NULL,
  sigma2 = NULL,
  contrasts = NULL,
  t_contrasts = NULL,
  f_contrasts = NULL,
  columns = NULL,
  output = c("stacked", "list"),
  robust_weights = NULL,
  ar_order = 0,
  drop_failed = TRUE
)

Arguments

B: Numeric matrix (p x V) of coefficients.
XtXinv: Numeric matrix (p x p), inverse cross-product of the design.
df: Residual degrees of freedom.
sigma: Optional numeric vector (length V) of residual std. dev.; ignored if sigma2 provided.
sigma2: Optional numeric vector (length V) of residual variances.
contrasts: Optional named list mixing t- and F-contrasts; vectors are t, matrices are F.
t_contrasts: Optional named list of numeric vectors (t-contrasts).
f_contrasts: Optional named list of numeric matrices (F-contrasts).
columns: Optional character vector (length p) naming coefficients; used for name matching.
output: Either "stacked" (default; tibble) or "list" (raw list of tibbles).
robust_weights: Optional numeric vector of robust weights or NULL. Used only for df adjustments.
ar_order: Integer AR order; used only for effective df adjustments.
drop_failed: Logical; drop contrasts that fail validation (default TRUE).

Value

A tibble with rows per contrast (default) or a named list if output = "list".

Details

Inputs mirror a standard GLM contrast computation: provide B (p x V), XtXinv (p x p), residual degrees of freedom df, and either sigma or sigma2 (per-voxel noise). Contrasts can be specified as a single mixed contrasts list or separately as t_contrasts (vectors) and f_contrasts (matrices). When contrast vectors/matrices are named (for vectors) or have column names (for matrices), names are matched to columns to determine the appropriate design indices; otherwise lengths must match the number of parameters p.